genirq/debugfs: Add missing sanity checks to interrupt injection

Interrupts cannot be injected when the interrupt is not activated and when
a replay is already in progress.

Fixes: 536e2e34 ("genirq/debugfs: Triggering of interrupts from userspace")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200306130623.500019114@linutronix.de